The US Navy has brought sixty-two Arleigh Burke class destroyers into service to date. The earlier ships – Arleigh Burke (DDG-51) herself is shown at the top – lacked a helicopter but the later Flight IIA ships – depicted by Gravely (DDG-107) above – were modified to provide this facility and additional VLS cells. These can be used to fire a range of munitions, notably Standard and ESSM surface-to-air missiles, Tomahawk land attack cruise missiles and the ASROC anti-submarine weapon.
Arleigh Burke Flight I ship USS Fitzgerald with TACTAS (tactical towed array sonar) in the center of the fantail, no helicopter hangars, and distinctive stacks.
Arleigh Burke Flight IIA ship USS Mustin without TACTAS in the center of the fantail, but with aft helicopter hangars, Phalanx CIWS mount and different exhaust stacks.
The last twenty-five years have seen a marked reduction in numbers of major surface combatants in service across the world’s navies. This trend has been combined with a tendency for these remaining combatants to have grown greatly in size and sophistication. The reasons for the numerical decline – the end of the Cold War and a sharp reduction in the need and willingness of the main protagonists to pay for such ships – are not hard to understand, but the trend towards larger, more complex ships warrants further explanation. So far as size is concerned, design influences such as improvements to accommodation and other crew facilities, the additional space utilised by stealth techniques, and even the impact of greater use of modular equipment. The increased focus on expeditionary activities, far from home bases, has also tended to emphasise further the benefits of volume for accommodation, fuel and stores.
Meanwhile, greater sophistication has been driven by evolving threats and the availability of technology, increasingly assisted by developments in consumer electronics, to provide an effective counter. Of these threats, that posed by saturation attack from anti-ship missiles had commonly been perceived as the most severe by the latter half of the Cold War. During this time, the expansion of the Soviet naval bomber force armed with stand-off air-to-surface missiles had particularly exercised US Navy planners. The capability of such systems, albeit of Western origin, were vividly demonstrated by the success of Argentine Exocet missile attacks on Sheffield and Atlantic Conveyor in the 1982 Falklands War. By this stage, however, the US Navy was already on the point of deploying its new Ticonderoga (CG-47) class cruisers, which provided a potent answer to the problem.
Existing warships had been vulnerable to air attack because defensive missiles needed a dedicated fire-control radar to guide them onto any target identified by the main search-and-surveillance radar. Essentially, each engagement required a separate fire-control radar throughout its entire course and only a small number of such radars could be carried. The Ticonderoga class were the first equipped with the Aegis weapons system, including its associated AN/SPY-1 electronically scanned or ‘phased’ radar arrays. The greater flexibility and precision of phased arrays – which use electronics to form and direct their radar beams – allowed Aegis to direct modified Standard series missiles (the Standard SM-2) towards incoming threats via mid-course guidance. This avoided the need for a separate fire-control radar until the final stages of an engagement. At this stage, ‘slaved’ illuminators were used to guide the semi-active Standard missiles onto the relevant target. This permitted a far greater number of incoming targets to be engaged than previously. The system’s precision and automated nature also allowed for fast reaction times. This is useful against ‘pop-up’ missiles – such as those fired from a submerged submarine – that may be a more likely threat in post-Cold War naval scenarios.
It was to be some years before other navies deployed weapons systems of equivalent capability to Aegis. Congressional reluctance to release the technology outside the US Navy meant that ten years were to elapse before Aegis was deployed by a foreign navy – onboard Japan’s Kongou (DDG-173) in 1993 – and only a handful of fleets have acquired the system to date. Moreover, Aegis’ sophistication was such that it was to be a further decade still before equivalent systems were developed by the main European navies, commencing with the Dutch De Zeven Provinciën in 2002. Initially largely installed in dedicated air-defence ships, phased arrays and their associated control systems are now increasingly common in all types of new surface combatants as the relevant technology becomes more affordable. Some of the emergent navies are also developing similar systems, rather than relying on imports from the United States or Europe. Notable examples include China’s Type 346 series of active phased arrays and the Israeli EL/M-2248 MF-STAR.3 The latter is being used in conjunction with the Indo-Israeli Barak 8 surface-to-air missile system onboard the new Indian-built Kolkata class destroyers.
Whilst this expansion of warship building and associated maritime technology industries to new countries has been another trend in 21st-century warship construction, it is important to note that its influence on major surface combatant design remains quite limited. With the exception of China – and possibly India – most major warship classes remain heavily influenced by prototypes and, certainly, weapons and systems developed in the traditional naval hubs of the United States and Europe. Even China, it is reported, has first relied on technology extracted from Russia and the West to build its own indigenous capabilities. Although it seems likely that this will change in future as emergent economies continue to broaden their skills, it remains a fact that the majority of the twenty-first century’s major surface combatant designs are essentially of Western or Russian origin.
Construction of major surface combatants for the US Navy since the end of the Cold War has been dominated by series production of the Arleigh Burke (DDG-51) class destroyers. Displacing nearly 9,000 tons in their original guise, the class is a multimission combatant with an emphasis on anti-air warfare. Preliminary design studies for the class started in the late 1970s as part of plans to replace older surface escorts. An important aim was to develop an affordable complement to the Ticonderoga class cruisers, the target cost being three-quarters of that of the larger cruiser. Principal sacrifices to achieve this aim included a reduction in fire-control illuminators (used in the final stages of an engagement) from four to three, omitting a helicopter hangar and air-warfare command and control facilities and a reduction in Mk 41 VLS missile cells to ninety from 122. Otherwise, the ships benefitted from being a purpose-designed platform for the Aegis system – the Ticonderoga class was a modification of the existing Spruance (DD-963) class hull – with a broader, more stable hull, improved survivability features and a significantly reduced radar cross-section. Propulsion is by means of a traditional COGAG plant. The lead ship was procured under the FY1985 construction programme. She was launched in September 1989 and commissioned on 4 July 1991.
Twenty-eight of the original Flight I and slightly modified Flight II Arleigh Burkes were completed between 1991 and 1999 before production switched to the modified Flight IIA design. These ships are around 500 tons heavier than the early ships and remedied a major perceived weakness of the original design by incorporating a hangar for two helicopters. They also have an additional six VLS cells. Thirty-four of this upgraded variant, benefitting from a series of incremental improvements as production progressed, were delivered from 2000 to 2012 before construction was halted in favour of the radical new Zumwalt (DDG-1000) class. However, a subsequent decision to terminate the Zumwalt programme – largely on cost grounds – meant that further orders were placed for the Flight IIA type from FY2010 onwards for delivery from 2016. Eleven additional ships will be built to this design before construction switches to a further improved Flight III variant, which will incorporate Raytheon’s improved air and missile defence radar (AMDR) in place of the SPY-1 arrays. AMDR – now designated AN/SPY-6 – will be particularly useful in improving capability against the threat from ballistic missiles. Ballistic missile defence (BMD) has become an important additional role for Aegis in the twenty-first century given the proliferation of first-generation tactical systems such as the Russian ‘Scud’. The greater potential of more recent ballistic weapons – not least China’s DF-21D anti-ship ballistic missile – means that an array conceived with this threat in mind is now desirable.
The longevity of DDG-51 class production is a tribute to the flexibility inherent in the original design, which now has the longest production run of any post-Second World War US Navy surface combatant. This has also brought the benefits of economies of scale from a long production run, with current ships costing around US$1.6bn – US$1.7bn per unit. However, there are signs that scope for further growth in the current design is now limited in terms of both internal volume and electrical generation and distribution capabilities. For example, although generation and cooling capacity is being increased in the Flight III ships, the version of the AMDR to be shipped is smaller and less-capable than that initially envisaged in a purpose-built ship. The Arleigh Burkes are also arguably expensive to operate compared with more modern, optimally-manned designs in spite of efforts to reduce crew size. For example, current complement of a little over 300 in the Flight I variant compares with c.190 in a British Type 45 air-defence destroyer.
The US Navy did have the answer to many of these issues in the Zumwalt class, a lean-manned (c.150 crew) cruiser-sized vessel of c.15,500 tons full load displacement incorporating a series of innovations in terms of hull form (use of a tumblehome hull), propulsion (integrated full electric propulsion), signature reduction, weapons systems and sensors. Armament includes two 155mm Advanced Guns Systems (AGS) optimised for shore bombardment and twenty quad Mk 57 peripheral VLS cells that are distributed around the ship’s outer shell to enhance survivability. A Dual Band Radar (DBR) similar to that specified for the new carrier Gerald R. Ford (CVN-78) was also originally planned but Raytheon’s AN/SPY-3 array has now been modified to perform all the functions intended for DBR as one of a number of cost-saving measures.4 However, an original programme that envisaged twenty-four ships being procured from FY-2005 onwards has ultimately seen production truncated at just three vessels as costs have spiralled upwards. Current estimates suggest total programme expenses of over US$12bn or more than US$4bn per ship. All-in-all, it seems that the US Navy were overly ambitious in attempting to introduce too many innovations simultaneously in one class of ship. At the same time, a renewed effort will have to be made to progress from the basic Burke hull sometime soon if the US Navy is not to lose its qualitative edge to foreign designs.
In the meantime, the DDG-51 design has formed the basis of Japan’s Kongou and Atago (DDG-177) classes, as well as the somewhat larger South Korean KDX-III Sejongdaewang-Ham type. The Aegis/SPY-1 combination has also been used in Spain’s F-100 Álvaro de Bazán class ‘frigates’ and their Australian Hobart class near-sisters. Finally, a ‘cut down’ version of the system, featuring smaller SPY1-F arrays with fewer than half the individual elements found in the standard panels, has been used in Norway’s Fridtjof Nansen class anti-submarine orientated frigates.